Heightened Senses
by ShirayukiTeikoku
Summary: My first fic. Tensions have been rising between Hisoka and Illumi, something's got to give. IllumixHisoka warning rated M for yaoi!
1. Chapter 1

Ok, so my first ever fic, don't expect much XD I basically impulsively threw this together after deciding to make a contribution to the world of fanfic (however bad that contribution may be XD)

And, I dunno what the title's relevance is. I'll work that one out later...

Let me know what you think (please be constructive - e.g "it sucks" won't help me improve lol).

I think I should have thought this through but ah well, enjoy.

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It was late into the night, even on the main highways traffic was becoming sporadic, the smaller streets were filled with the silence of the now sleeping city, which was only mildly disturbed by a rustling in a patch of hedges.

Out of the dark undergrowth a lone figure appeared quite suddenly. The figure seemed to flicker like some dark apparition, appearing within the golden pools of light cast by the street lamps before being swallowed again by the darkness.

Marching stiffly, the figure rounded a corner into a pitch black alley, once again vanishing into the shadows before reappearing in the light cast by a near by sign as he ascended the rickety wrought iron stairs of a seemingly empty and derelict apartment. All the windows were black as the night, save for one on the top floor, from which the thinnest bar of light could be seen peaking out between heavy curtains.

The figure continued it's journey along the bare, unlit corridors of the apartment block, following the faint light form the door at the very end of the corridor, his steps steady and sure despite the lack of light.

A foot from the door, it was obvious the room was the only room in the building in use. The door was spotless and considerably heavier than all the other doors, the lock much much sturdier than the run-of-the-mill locks of the other apartments. The figure whipped out a key and briskly unlocked the door, pushing it open with apparent ease despite it's weight.

"Ah, Illumi, I didn't expect you here so soon,"

"I told you my latest job was not going to be too time consuming. Why did you call me here, Hisoka? Your message was rather vague and I don't have time to waste on you,"

Illumi crossed the room and took a seat on the edge of the simple double bed Hisoka was also sat on. The room, despite it's more inhabitable appearance compared to the rest of the building was still one of function rather than for comfort. There were no decorations and only the necessary furniture, the bed, a desk an chair, a cupboard, it was merely a temporary base no a permanent residence, a meeting point for the two to correspond without risk of being overheard.

"I need you to act as my dummy and fill in for me with the Spider," Hisoka replied as he sat casually shuffling a deck of playing cards.

"What are you going to be doing in the mean time?" Illumi asked as he began removing the pins form his head. Hisoka turned his head slightly to watch before answering.

"Just checking how the fruit is doing, I'm becoming impatient for it to ripen," Hisoka let out an unsettling laugh. Illumi could hear a kind of manic glee starting to affect the other's tone.

"Very well. What menial task will I have to do this time?"

"Ah, I don't know just yet," Hisoka sounded distracted and Illumi could tell exactly where the other's mind lay. The deranged look of glee spreading across Hisoka's face was all to obvious to the assassin. It seemed to him Hisoka was getting worse at containing his excitement. Illumi hadn't know him long, but gained enough of an understanding of the other that he would not have expected such a reaction in lieu of the meager young hunter Hisoka had become fixated on.

"I think you're overestimating the boy. I seriously doubt he will have improved significantly in this short space of time. He's not worth your attention, a waste of time, you should just dispose of him,"

Illumi disproved of the boy's relationship with his younger brother. An assassin did not have friends. Or at least if he did the relationship was purely one that would be beneficial to the assassin. Illumi did not see how Killua would gain anything from his "friendship" with Gon.

While Illumi had been contemplating this, he had not noticed his companion's gaze upon him.

"Oh really? Did you not say yourself that he has potential?" Hisoka smirked. Riling the stony faced assassin was one of his favorite pass-times.

Illumi's expression did not change but to Hisoka his eyes seemed even colder than usual.

"Yes I believe he has potential but not as much as you give him credit for. Where you to fight head on, he could train for another hundred years and he would be no match for you," Hisoka's eyes widened slightly at the unexpected compliment of his skills.

"Hmm, then about you? Would he pose a threat to a great assassin such as yourself?" Usually Illumi would have seen straight through Hisoka's intentions but it was now his mind that was no longer focused on the conversation. That boy's closeness to his brother more than he would admit even to himself.

"He might put up a fight but it wouldn't be a greater threat than I have overcome in the past" Illumi stated, his tone noticeably more frigid, and Hisoka certainly did notice.

"You don't think you might be underestimating him? Even at his current level, look what he did to your arm," Hisoka remarked, his grin widening. This jarred Illumi's attention back to him in an instant.

"Are you suggesting he would be at all challenging to fight?" Illumi shot at Hisoka, his tone still flat and his face still devoid of emotion, yet his response was a little too fast, a little too sharp. Hisoka almost didn't believe his luck. He suppressed a chuckle.

"My, my aren't we getting excited, you honestly think I'm suggesting he's a match for you? If he was at your level you don't think I'd have fought him by now? Or does is it his friendship with your brother? Does their closeness bother you so-" Hisoka had hit the nail on the head. As a result he was cut off by a sudden pin flying at him with deadly accuracy. Hisoka almost failed to dodge it. Had it hit, the pin would have shot strait into his mouth right through his tongue.

The sudden attack had actually taken Hisoka by surprise. He hadn't expected his taunts to agitate Illumi this much, his expression was beginning to darken. At this rate he would have an excuse to fight Illumi without it being grounds enough to break off their agreement. He could put it off as a careless spat, pretend he wasn't fighting seriously and (half) truthfully suggest he hadn't expected Illumi to become so enraged. Now it was becoming increasingly hard to hide his excitement. He could feel a mix of laughter and a suppressed moan bubbling in his throat. The anticipation of the upcoming fight was electrifying.

"Ah so it really does bother you. And I thought assassin's were supposed to be devoid of emotions, weren't they...how did you phrase it? 'Unnecessary?'"

"Don't be ridiculous, of course emotions are unnecessary but someone like you who's ruled by your own careless whims would not understand, it's what holds you back from becoming stronger, Hisoka," Illumi replied sharply. Hisoka could feel Illumi's death aura beginning to seep out, it sent shivers through his body causing his expression to become even more elated. The sensation of Illumi's fury was almost too much for him, he was beginning to tremble with excitement.

"Is that a challenge? But I don't really feel like fighting you in this worn out state you're in," Hisoka turned his back in mock indifference when in fact he was concealing his arousal. He could feel a tingling spreading through his body, his excitement was becoming unbearable. If things didn't kick off soon he wouldn't be able to control himself any longer.


	2. Chapter 2

Perhaps Illumi was genuinely tired from his previous job or perhaps it was simply because Hisoka had hit an incredibly sensitive nerve when he struck with such precision on the topic which had been fermenting in his mind for many a night, either way, Illumi snapped.

All the usual tactics and strategies he applied to making a killing, especially with an opponent of Hisoka's level, flew out of his head as he shot strait at Hisoka, a handful of pins between his fingers.

Hisoka dodged them with ease. He now had the advantage. Under normal circumstances, Illumi would be an exceedingly difficult opponent but in his incensed state, he was playing right into Hisoka's hands.

Hisoka lazily threw a few cards at the furious assassin, Bungee gum secretly attached to each. As predicted Illumi had no trouble avoiding their path but had not accounted for the Bungee gum. The cards embedded themselves in Illumi's left arm and both legs from the ankle to the knee. Hisoka was taken aback by how suddenly Illumi went down. It was clear from the assassin's expression that he was too.

He become even more confused when he was unable to leap to his feet again. His head began spinning and Illumi began to feel dizzy and disorientated, his limbs becoming sluggish and uncooperative.

"I didn't expect the first strike to hit! My..." Hisoka's tone dropping as he surveyed the struggling assassin The fight hadn't been nearly long enough. He felt extremely disappointed and dissatisfied that he had underestimated the assassin's exhaustion. True, he'd heard his target was considerably strong but hadn't really though his strength was anything of a challenge to someone of Illumi's level. Perhaps he really did let his whims get the better of him a little too often. No matter. Hisoka had other ways of venting his heightened excitement.

Advancing on the prone figure, Hisoka licked his lips as he observed the assassin's breath becoming more ragged. The poison on his cards certainly was fast acting.

Hisoka placed a finger under Illumi's chin, slowly raising his head until their gazes met.

"How does it feel? My poison, I mean," Hisoka grinned broadly as Illumi's brows furrowed at his words.

"It's wonderful isn't it! Not lethal of course, you know I would never kill someone in such a boring way. But it is extremely paralytic," Hisoka plucked out all the cards piercing Illumi with a light tug at the strands of Bungee gum attached, before gathering the assassin in his arms and carrying him briskly towards the bed.

"Wha..." Illumi found he barely had the strength to speak. His tongue felt heavy and his brain was completely addled, he was now having trouble focusing his gaze, however, he was aware of a growing burning sensation in the pit f his stomach and a strange tingling that seemed to be making his body hyper-sensitive. He found himself beginning to feel rather flushed as if he was absorbing the heat from the man carrying him and become oddly conscious of the sound of Hisoka's heart beating close to his ear.

Hisoka tossed Illumi lightly onto the bed and crawled onto it so that he hovered above him making Illumi squirm. He could feel a dull ache growing in his crotch and his pants were beginning to feel uncomfortably tight. Illumi suddenly realized the poison Hisoka had intoxicate him with was doing more than just paralyzing him.

"You-" Before Illumi could breath more than a single word Hisoka's lips were on his, the warm, demanding pressure of them more intoxicating to him than the poison working in his veins. As Hisoka's tongue forced it's way into his mouth and began exploring Illumi felt a sudden spike a pleasure in his crotch, causing him to gasp into Hisoka's kiss. Hisoka withdrew, chuckling deeply. The sound only served to send more heat rushing to the assassin's crotch. He was now panting hard and beginning to shake. As he gazed up helplessly at Hisoka he became aware of the fact Hisoka seemed to be even further gone than himself.

His gold eyes were half lidded, his breath more ragged than Illumi's and he was all but shuddering in anticipation as he gazed hungrily down at the figure lying under him.

With his hair fanning out around his pale face, his own dark eyes half closed, gasping and shivering Hisoka could not imagine a more tempting vision. Struggling to support himself, Hisoka stopped trying, jerkily lowering himself to press flush against Illumi's heated body. The pair both groaned the contact. Hisoka ground against the trembling figure below him, reveling in the pleasure of pressing their aching needs against each other.

"Hi...Hi..soka..." Illumi could hardly speak, he found it took most of his energy just to hold back the moans that were threatening to escape, as if his heavy gasps were humiliating enough. He withered in discomfort.

Hisoka, who had turned his attention to Illumi's neck, placing kisses all down it to his collar bone, ignored the assassin's struggling and continued his ministrations along Illumi's body. As he began to kiss and suck Illumi's collar bone he felt a hand tug lightly on his shirt.

So he was already beginning to fight the poison? Impressive. Hisoka felt himself become even harder. This was becoming far too much for him. He almost came seeing the desperate expression on Illumi's face.

"Please..."

Hisoka moaned gutturally, pulling himself up and all but tearing Illumi's clothes from him before beginning on his own. He moaned again at the relief after removing his pants and began sucking and licking Illumi's chest.

"Nnngh...ah..."

The assassin was now moaning without restraint, his will power completely drained. The pleasure jolting through his body was almost agonizing and his erection was now throbbing and aching with arousal.

"Ah!" Illumi suddenly yelled out, his body jerking with a sudden spike of pleasure as Hisoka began to pay his nipples special attension.

"Hi-Hisoka! Ah! S...Stop... It's too - ah- it's too much..."

Illumi bucked and squirmed as the tension in his belly began to tighten. Hisoka groaned at the sight and the noises Illumi was making. He was getting too close to the edge, at this rate his wasn't going to last long enough for the real fun to begin.

Speading Illumi's quivering thighs, he forced his tongue into the assassin's tight heat.

"H-aah!" Illumi let out a choked cry. To his over sensitive body the feeling of Hisoka's tongue twirling inside him was like pins to every nerve in his body. He whimpered desperately, fighting the sharp shocks of intense pleasure racking his body.

"Ah! I...I can't...ngh!" Illumi felt a sob leave his throat and felt a faint wave of confusion.

Hisoka glanced up at him, his expression unreadable. Pressing himself against Illumi, he pulled him close, his hand cradling the assassin's silky head, his other arm holding him in place before slowly pushing into him.

A half moan, half scream broke from Illumi's lungs. He clung tightly to Hisoka, the sudden mix of pain and pleasure too intense for him to handle. Hisoka gave a low groan as he fought to keep from simpy pounding Illumi into the bed.

"Hi-Hisoka - ngh - please," Illumi chocked out, his voice just above a whisper.

"M-move,"

Hisoka groaned again before beginning to thrust into Illumi's tight heat. His body was tense and aching with arousal and he was almost delirious with pleasure, struggling to keep an even pace as he felt Illumi's inner walls squeeze him tightly. He let out another deep, low groan, his voice rising with every thrust. He could almost feel his orgasm, his body already beginning to jolt with pleasure.

Illumi's voice was also rising, each cry more intense than the previous. As Hisoka pressed their lips together, forcing his tongue into every corner of Illumi's mouth, Illumi felt the tightness in his groin intensify unbearably.

He let out an intense moan in rapture as his orgasm hit suddenly, bursting through him. As it washed over him, enveloping his whole body with the most overwhelming pleasure imaginable, the clenching of his walls on Hisoka's throbbing erection forced him over the edge too.

Roughly riding out their orgasms, Hisoka thrust a few more times into Illumi before collapsing onto him as the both lay bathing in a thick, blissful afterglow.

Rolling onto his side, Hisoka drew the exhausted Illumi to his chest, wrapping his arms firmly around him. Illumi murmured blissfully before lazily pressing himself against Hisoka. And with that the pair fell fast asleep.

... ... ... ... ...

let me know what you think. I hope that wasn't too terrible XD


	3. Chapter 3

Illumi awoke to the warm, bright beams of sunlight glimmering at the edges of the heavy curtains of the apartment room. He felt oddly as if he could already feel the sun's warmth despite the curtains almost completely shielding him from it. Surveying his surroundings for a moment, he discovered the reason behind this feeling.

Hisoka smiled brightly at him, propped up casually on one arm, his bare torso exposed, the rest of his body covered by the light bed sheets. Illumi found himself observing the man's muscular body with uncharacteristic fascination.

"Good morning, Illumi," Hisoka's cheerful greeting brought Illumi's attention back to the man's face. He found himself almost startled, when had he let his guard drop to such a degree? The previous nights events whirred through his mind and he found himself suddenly hyper-alert. He slowly raised himself to a sitting position, refraining from making any sudden movements so as not to alert Hisoka as to his current state of disarray.

"I assume you have a good explanation for last night?" Illumi asked coldly. This served only to broaden Hisoka's grin.

"Are you telling me I was the only one who enjoyed them self?"Hisoka asked playfully. As Illumi's mind choose to rather unhelpfully select and playback particularly heated moments from the previous night, Illumi struggled to retain his calm. The thought of killing Hisoka has crossed Illumi's mind the moment his memories had returned to him yet some part of him kept deciding against this yet he was unable to identify the reason. The man had not only managed to wound him but also paralyze him only to take advantage of him. No assasin, let alone a Zoldyck should allow such acts to go unpunished.

"You surely don't think your actions will have no repercussions" Quite suddenly Illumi leapt atop of Hisoka, sitting astride his chest and wrapping his hands around his throat. Hisoka simply continued to smile brightly, completely unperturbed.

_He knows,_ Illumi realised, _knows that I won't do it. But why?_ Illumi wondered, why wouldn't he kill Hisoka after what he'd done to him. He looked down at the man under him. Hisoka's hair, already disheveled from sleep was now splayed around his head in red waves and his eyes golden eyes gleamed with a certain deviance that made Illumi's heartbeat quicken. Suddenly Illumi became strangely aware of how vulnerable Hisoka was, completely naked beneath him with Illumi's hands at his throat. Illumi could suddenly feel a kind of tense, repressed excitement building. He could feel the man's bear chest rising and falling under his weight with a slight unevenness Illumi knew was certainly not fear. It made him remember being in Hisoka's embrace, hearing his ragged breaths as he thrust into him. Illumi was beginning to feel his temperature rising. Hioka clearly noticed. Illumi felt the rise and fall of Hisoka's chest become even more ragged.

His grip loosening, Illumi found himself leaning closer to Hisoka's face, his jet black curtains of hair falling to the pillow to mingle with Hisoka's. There was noticeably more heat radiating from Hisoka as Illumi leaned in even further and he too could feel his body reacting.

He paused only for a second before pressing his lips firmly against Hisoka's. Hisoka groaned into the kiss, his body shuddering under Illumi's at the contact. Illumi began to slide himself down Hisoka's body until they were flush against each other, the friction of the movement and the press of their bodies serving to stimulate Hisoka's body, already hyper sensitive from the tension between the two. he allowed a throaty moan to escape his lips as Illumi began to continue lower with his kisses.

The memories of the night before, the rush of adrenaline from the thoughts of killing Hisoka ontop of the sight of Hisoka naked and aroused and the feeling of dominance were causing Illumi's hormones to descend out of control. His hands shook as he began to explore the expanses of muscles along Hisoka's lithe frame, his own body already aching with arousal. As he ran his hands over Hisoka's chest, he arched to meet the touch, his breaths coming in heavy gasps.

Illumi found Hisoka's weeping erection and began to gently lick it causing Hisoka to arch and cry out from the jolt of pleasure. As Hisoka glanced down at Illumi as he conducted his ministrations the almost feline grace of the assassin as he licked slowly along his aching shaft brought Hisoka much too close to his climax.

"A-ah not so fast!" Hisoka threaded his fingers into Illumi's silky hair and tugged him away from his pulsing need. Illumi allowed a small smile o grace his lips and it was worth the effect it has on the already desperate Hisoka.

"D-don't you think we...we should get to the real fun n-now?" Hisoka, his body alight with passion, and his mind set only to his own need and the object of his desire before him, was struggling to form any logical thoughts, let alone convert them into coherent words. Illumi stroked Hisoka's lower belly causing him to let out a hiss at the feeling it produced.

"Very well. It's a surprise to see you so impatient, Hisoka," Illumi said, reveling in the utter mess he has made Hisoka. He was finally beginning to understand the pleasure Hisoka felt in teasing his prey, having power over another was indeed enjoyable.

Illumi, feeling curious as to how far he could take things, made a show of licking his fingers before preparing Hisoka, feeling satisfied as Hisoka squirmed, his inner muscles already quivering as Illumi slowly pushed two fingers into him.

By the time Illumi was satisfied with his preparation of Hisoka, the man was gasping and whimpering, his body jolting uncontrollably.

"I-Illumi..." Illumi lined himself up and began to press into Hisoka, who gave a low groan, bucking his hips trying to get Illumi to speed up. Illumi was now in no position to hold back. As soon as he was fully sheathed he began thrusting rapidly into Hisoka who was far to aroused to notice any discomfort.

Even in his state Hisoka was amazed at the level of pleasure that just kept building in his body. Even when he was sure he would blow a whole new level of intense pleasure would unfold within him. When Illumi began hitting his sweet spot he was already deafening himself with his own screams. The sudden intense spike in pleasure made his scream catch in his throat and all that escaped was a strangled moan.

Illumi was now becoming vocal himself, every breath coming as a labored gasp littered with moans and Hisoka's name. His brows creased with the effort to carry on moving against the tide of overwhelming pleasure that was threatening to drown him.

"Aaah! I ca...I can't...any ..ger" Hisoka gasped out. Feeling Hisoka clamping around him tighter and tighter Illumi understood perfectly and merely gave a low groan in response. He was only able to thrust one more time before Hisoka suddenly yelled out, his eyes clamped shut as a furiously powerful orgasm crashed over him, his entire body withering in the almost excruciating pleasure. Illumi joined him in the rattling intensity of his climax letting out a muted whimper as they both shakily rode out their orgasm.

When both of their bodies had finally settled, the jarring waves of pleasure faded, Illumi collapsed onto Hisoka and both slid onto their sides, panting and holding each other.

It was quite sometime before Hisoka could gather the strength to speak.

"Am I to take it that I'm forgiven?" Illumi could not say no to a smile like that. The gaze Hisoka held him with was like nothing he'd ever experienced. Finding his words not leaving his mouth, Illumi has to swallow before speaking.

"Yes but you are never to poison me again, Hisoka," Hisoka chuckled and held Illumi closer.

"Don't worry, I won't do it again,"

He knew he would never again need to.

-The End-

Please tell me what you think ^_^  
sorry if it was rather OOC and full of mistakes XD


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